Whats the truss rod?

PJVITALOGY

haha sorry this is probably a real stupid question but ive always wondered what it is

who's_pearljam?

Pretty much any modern guitar has a truss rod in the neck.
It is a metal rod that hooks in one end of the neck, and has a threaded end on the other. There is a nut on the end of it that adjusts it, usually under the little cover by the tuners, or in the sound hole of the acoustic. with a lot of strats, you have to take the neck off to access it.
What the truss rod does is to add strength to the neck, and makes it adjustable. Wood moves, either temperature related or moisture, or stress of different strings, so the truss rod will bend the neck to the right shape, essentially. When you tighten the truss rod, it pulls the neck backward, when you loosen it, the neck bends forward. If you change from 9 to 11 gauge strings, for instance, you usually need to tighten the truss rod nut bit by bit because the added tension pulls the neck forward, so the rod counteracts that and straightens the neck.

This lesson brought to you by "Bob", when he should be making a few phone calls, but is instead, slurping down coffee.